1. Field of the Invention
The present invention relates to a leather-wrapped steering wheel for steering a vehicle and to a manufacturing method. The leather-wrapped steering wheel of the present invention is provided with a ring portion. The ring portion is provided with a covering layer, with the leather covering that covering layer.
2. Description of Related Art
Conventionally, in a leather-wrapped steering wheel, where a ring portion covering layer is covered with leather, the leather extends along the surface circumferential direction of the ring portion, and has distal edges. The covering layer is provided with annular grooves formed in the circumferential direction on the cross-section of the ring portion. Further, the distal edges of the leather are fitted into the annular grooves of the covering layer (see Japanese Laid-open Patent Publication 226338/1998).
In such a leather-wrapped steering wheel, to enhance the outer appearance of the leather, the peripheries of the annular grooves are formed of hard material such as hard synthetic resin or the like. That is, by forming the peripheries of the annular grooves with hard material, the distal edges of the leather can be acutely bent around the rims of such annular grooves and then fitted into the annular grooves. Further, parts of the leather in the vicinity of the annular grooves which protrude from the annular grooves are formed in an apparent sharp edge shape thus enhancing the outer appearance of the leather.
However, in case of forming the peripheries of the annular grooves with hard material such as hard synthetic resin or the like, it is necessary to properly set the length of the leather. This is because if the length of the leather is too long, when the distal edges of the leather are fitted into the annular grooves, the leather gives rise to an extra portion and wrinkles appear at the peripheries of the annular grooves. On the other hand, if the length of the leather is short, even when the distal edges of the leather are fitted into the annular grooves, the distal edges of the leather can come out from the annular grooves.
Further, in case an adhesive agent is used to prevent the distal edges of the leather from coming out of the annular grooves, the peripheries of the annular grooves become sticky with the adhesive agent.
Still further, where a spatula is used to fit the distal edges of the leather into the annular grooves, the use of the spatula however may injure the distal edges of the leather.
It is an object of the present invention to provide a leather-wrapped steering wheel and a method for manufacturing the same where the distal edges of the leather easily fit into annular grooves while keeping the distal edges of the leather and the peripheries of the annular grooves neat and clean. That is, it is an object of the present invention to provide a leather-wrapped steering wheel and a method for manufacturing the same which can carry out the leather wrapping operation neatly and simply.
The object of the present invention can be achieved by the leather-wrapped steering wheel which has a following constitution.
The leather-wrapped steering wheel of the present invention is provided with a ring portion which is gripped at the time of steering. The ring portion includes a core, a covering layer which covers the core and the leather wrap which covers the covering layer. The covering layer is provided with annular grooves in the circumferential direction along the cross section thereof. The leather is constituted such that binding strings are provided to distal edges of the leather along the surface circumferential direction of the ring portion and the distal edges are fitted into the annular grooves so as to make the leather cover the covering layer. The binding strings are disposed at the distal edges of the leather such that the binding strings are restricted from moving in the direction along the surface circumferential direction of the ring portion and are made to pass through the distal edges of the leather such that the binding strings are movable along the annular grooves. The distal edges of the leather are disposed in the annular grooves together with the binding strings and then both ends of the binding strings are pulled and tied together so as to make the distal edges fitted into the annular grooves.
In the leather-wrapped steering wheel of the present invention, by merely pulling and tying the binding strings in the inside of the annular grooves after disposing the distal edges of leather in the annular grooves together with the binding strings, the distal edges of the leather can be fitted into the annular grooves.
Here, the movement of the binding strings along the surface circumferential direction of the ring portion is restricted while the binding strings are made to pass through the distal edges of the leather such that the binding strings are movable along the annular grooves. Accordingly, even when the binding strings are pulled, the binding strings are not slipped off from the distal edges of the leather along the plane circumferential direction of the ring portion. Thereafter, by tying the binding strings, the distal edges of the leather are shrunk along the annular grooves so that the distal edges can be fitted into the annular grooves.
Further, by tying the binding strings, the distal edges of the leather can make portions thereof through which the bindings strings are made to pass assuredly disposed on the bottom surfaces of the annular grooves. Accordingly, the distal edges of the leather can be properly positioned and then are fitted into the annular grooves.
Further, the distal edges of the leather can be fitted into the annular groove by simply tying the binding strings without using the adhesive agent or the spatula so that the distal edges of the leather and the peripheries of the annular grooves are neither smeared nor injured.
Accordingly, with the leather-wrapped steering wheel of the present invention, the leather wrapping operation in the vicinity of the annular grooves can be carried out neatly and simply.
Loop portions may be formed on the distal edges of the leather and the binding strings may be made to pass through the inside of the loop portions.
Further, the binding strings may be stitched to the distal edges of the leather in the direction along the annular grooves. In this constitution, the loop portions need not be formed on the distal edges of the leather. Accordingly, compared to the case where the loop portions are formed, this constitution can reduce the processing man-hours and the processing cost for loop portions. Further, the leather may be provided with upper and lower extension portions. These upper and lower extension portions cover front and rear surfaces ranging from the covering layer of the ring portion to the covering layers of the spoke portions which extend from the covering layer of the ring portion and are disposed on front and rear surfaces of the covering layers of the spoke portions by stitching the peripheries thereof to each other. In this case, by making use of remaining portions of the binding strings which remain after tying portions of the binding strings in the annular grooves, the peripheries of the upper and lower extension portions can be stitched to each other. Accordingly, the distal edges of the binding strings can be effectively, thus eliminating the need to cut off of the distal edges of the binding strings.
Further, the object of the present invention can be achieved by the following method for manufacturing leather-wrapped steering wheels. In the method for manufacturing leather-wrapped steering wheels of the present invention, the leather-wrapped steering wheel is provided with a ring portion which is gripped at the time of steering. The ring portion is comprised of a core, a covering layer which covers the core and leather which covers the covering layer. The covering layer is provided with annular grooves which are formed in the circumferential direction of the cross section of the ring portion. The leather is constituted such that the leather has distal edges thereof along the surface circumferential direction of the ring portion fitted into the annular grooves so as to cover the covering layer. The leather is comprised of a body portion which covers the covering layer of the ring portion by stitching the peripheries to each other at the inner peripheral side of the ring portion and upper and lower extension portions which cover front and rear surfaces ranging from the covering layer of the ring portion to the covering layers of spoke portions which extend from the body portion of the ring portion by stitching peripheries to each other. Further, binding strings are made to pass through distal edges of the body portion of the leather such that the movement of the binding strings along the surface circumferential direction of the ring portion is restricted while the binding strings are movable along the annular grooves. Then, at the time of mounting the leather, the distal edges of the body portion of the leather are disposed in the annular grooves together with the binding strings. Then, by pulling both ends of the binding strings together and tying them, the distal edges of the body portion of the leather are fitted into the inside of the annular grooves. Further, by stitching the peripheries of the upper and lower extension portions each other by making use of the remaining portions of the binding strings after tying the binding strings at positions in the inside of the annular grooves, the leather-wrapped steering wheel can be manufactured.
According to the method for manufacturing leather-wrapped steering wheels of the present invention, by merely tying the binding strings in the inside of the annular grooves and pulling the binding strings, the distal edges of the body portion of the leather can be properly positioned and fitted into the inside of the annular groove without using either an adhesive agent or a spatula. Accordingly, the distal edges of the leather and the peripheries of the annular grooves are neither smeared nor injured. As a result, the distal edges of the body portion of the leather can be fitted into the annular grooves neatly. Further, by making use of the remaining portions of the binding strings which have portions thereof tied in the annular grooves, the peripheries of the upper and lower extension portions of the leather are stitched each to other thus manufacturing the leather-wrapped steering wheel. Accordingly, the binding strings are effectively utilized. Still further, after properly positioning the distal edges of the body portion of the leather and fitting them into the annular grooves, the upper and lower extension portions are stitched each other. Accordingly, the upper and lower extension portions can be also properly positioned and disposed. As a result, the outer appearance of the leather wrapped portions is enhanced.
At the time of stitching the peripheries of the upper and lower extension portions each other, first of all, using one end of each binding string, the peripheries of the upper and lower extension portions are stitched to each other in a staggered stitching pattern (zigzag chain stitching pattern). Then, the other end of each binding string is made to pass through the rear surface side of the zigzag chain stitched portion. Finally, the two ends of the two binding strings may be tied with each other at the stitching end position of the zigzag chain stitching.
In such a manufacturing method, the other end of the binding string is made to pass through the rear surface side of the stitched portion and is tied with one end of the binding string which binds the peripheries of the upper and lower extension portions to each other. Accordingly, the slipping off of the binding strings from the leather can be prevented so that the peeling off or the dislocation of the leather can be suppressed.
Incidentally, in the conventional staggered stitching (zigzag chain stitching), the end portions of the string are individually tied after performing the zigzag chain stitching thus only forming large knots respectively at the end portions. Accordingly, the knots are liable to be slipped off from the leather. However, in the above-mentioned manufacturing method, both end of the string are tied with each other such that the front and the rear of the leather wrap the ends of the strings and hence, the slipping off of the string from the leather can be prevented.
These objects and advantages of the present invention will become further apparent from the following detailed explanation.